Project Summary. Primary care (PC) is well-positioned to detect and address unhealthy drinking and alcohol use disorder (AUD), yet most PC settings have notable gaps in providing alcohol-related care. One way to improve alcohol-related care is to use standardized measurements to screen for unhealthy alcohol use and to assess AUD symptoms, which informs clinical care by detecting unhealthy drinking, assessing AUD severity, informing decisions about AUD treatment intensity, and monitoring clinical outcomes over time. Researchers and national agencies are increasingly calling for the use of standardized measures of unhealthy drinking and AUD symptoms in routine PC settings; however, surprisingly little is known about how such measures perform or what they indicate about health risks when they are used in the context of routine PC?i.e., administered in routine appointments and documented in electronic health records (EHRs). We propose to leverage a large and novel EHR dataset from Kaiser Permanente Washington, a large integrated regional health system. The dataset will include: the AUDIT-C alcohol screening measure, completed as part of an annual screen by >250,000 patients (89% of adults who attend PC appointments); a novel patient-reported AUD symptom checklist that is based on the 11 DSM-5 AUD criteria (?DSM-5 checklist?), completed by over 4,000 patients (>70% of those with AUDIT-C scores ? 7); and diverse health outcome measures available from EHR, administrative, and claims data. The 2-year developmental R21 phase includes psychometric analyses that evaluate the DSM-5 checklist as a scaled measure of AUD severity and the consistency of its performance across demographically diverse subgroups; to our awareness, this is the first study to evaluate any standardized patient-reported AUD symptom measure integrated into routine PC. Cross-sectional analyses will examine associations between the AUDIT-C, DSM-5 checklist, and important health outcome measures known to be associated with drinking, including systolic blood pressure, patient-reported depression symptoms, hospitalizations for alcohol-attributable conditions, all-cause hospitalizations, and all-cause mortality. The R21 will also achieve milestones demonstrating readiness for the R33 phase. During the 3-year R33 phase, longitudinal analyses will test whether the AUDIT-C and DSM-5 checklist are associated with subsequent health outcomes and whether within-person changes in AUDIT-C scores over time are associated with changes in health outcomes. To our awareness, this work will be the first to evaluate a patient-reported AUD symptom checklist in any routine PC setting and the first to evaluate the AUDIT-C in any non-veteran routine PC setting. This research will improve clinical care by helping providers and patients understand the information provided by these scaled patient-reported measures and their associations with important adverse health outcomes. The work will also provide a foundation for future studies that use patient-reported EHR- based measures in pragmatic studies, implementation trials, and quality improvement initiatives.